Vagal Nerve Stimulation for Functional Dyspepsia and Gastroparesis

Eligibility Criteria

• 1. Volunteers, female and male, between 18 and 65 years of age.
• 2. For healthy volunteers, ability to undergo MRI for up to 2 hours.
• 3. For Functional Dyspeptic patients, diagnosis according to the Rome III criteria for both PDS and EPS subtypes.
• 4. For Gastroparesis patients, diagnosis will include the following criteria:
• * symptoms of gastroparesis of at least 12 weeks duration (does not have to be continuous) with varying degrees of nausea, vomiting, early satiety, and/or post-prandial fullness
• * an idiopathic etiology
• * abnormal gastric emptying scintigraphy (GES) results using a 4 hour low fat Egg Beaters® protocol within the last 6 months with either a gastric emptying rate \> 60% retention at 2 hours and/or \>10% retention at 4 hours.
• 1. History gastric/esophageal surgery
• 2. Any alternative treatment (e.g. acupuncture, hypnosis etc.) two weeks prior to the study or during the study period.
• 3. Illicit drugs or opioid use.
• 4. History of arrhythmias.
• 5. Implanted pacemaker.
• 6. Epilepsy or a prior history of seizures.
• 7. For Gastroparesis patients, inability to comply with or complete GES test (including allergy to eggs).
• 8. Pregnancy or nursing or plans to become pregnant.
• 9. Inability to provide informed consent.
• 10. BMI more than 32 and/or weight \> 235 lbs. (limits of the MRI table).
• 11. Contraindications for MRI: High magnetic fields may pose a serious health hazard to subjects with implanted ferromagnetic objects. Every subject in this study will be carefully screened before entering the high magnetic field shielded room to collect a precise outline of the subject's medical history. Subjects with the following characteristics/disease may not be eligible to participate in the study and will require additional screening:
• * History of Head Trauma
• * Any metallic implants (e.g. braces or permanent retainers)
• * Tattoos with metallic ink above the nipple line
• * Surgical Aneurysm Clips
• * Cardiac Pacemaker
• * Prosthetic Heart Valve
• * Neurostimulator
• * Implanted pumps
• * Cochlear Implants
• * Metal rods, Plates, Screws
• * Recent Previous Surgery
• * IUD
• * Hearing Aid
• * Dentures (which might create NMR artifacts)
• * Metal Injury to eyes
• * Pregnancy or plans to become pregnant
• * Breast Feeding
• * Meniere's Disease
• * Transdermal (skin) patches such as NicoDerm (nicotine for tobacco dependence), Transderm Scop, or Ortho Evra (birth control)
• * Claustrophobia